This section introduces aspects that may facilitate a better understanding of the disclosure. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art.
In wireless systems, there is a requirement for high throughput, and future wireless networks are being designed with a target data rate of several Gbps. To reach such high bit rates, a solution exploiting a large number of antennas, referred to as massive multiple input multiple output (MIMO) has been considered in some communication systems. Though massive MIMO was originally envisioned for use in a time division duplex (TDD) system, but it can potentially be applied also in a frequency division duplex (FDD) system.
Massive MIMO makes a clean break with current practice through use of a large number of serving antennas that are operated coherently and adaptively. The use of the large number of antennas facilitates focusing signal energy into a small region in space. As a result, massive MIMO brings huge improvements in throughput and energy efficiency, in particular when it is combined with simultaneous scheduling of a large number (e.g., tens or hundreds) of terminals.
Other benefits of massive MIMO include an extensive use of inexpensive low-power components, reduced latency, simplification of the media access control (MAC) layer, and robustness to interference and intentional jamming. Anticipated throughput of a massive MIMO system depends on propagation environment providing asymptotically orthogonal channels to terminals, and no limitation in this regard has been disclosed by experiments so far.
While massive MIMO renders many traditional research problems irrelevant, it uncovers entirely new problems.